枚举 + 条件判断
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
bool check(int n)
{
if (n % 7 == 0) return false; //判断能否被7整除
while (n) //判断十进制表示中 各个位上是否等于 7
{
int t = n % 10;
if (t == 7) return false;
n /= 10;
}
return true;
}
int main()
{
int n, res = 0;
cin >> n;
for (int i = 1; i <= n; i ++ )
{
if (check (i))
res += i * i;
}
cout << res << endl;
return 0;
}